Semiconductor package having multi-tier bonding wires and components directly mounted on the multi-tier bonding wires

ABSTRACT

A semiconductor package includes a carrier substrate having a top surface, a semiconductor die mounted on the top surface, a plurality of bonding wires connecting an active surface of the semiconductor die to the top surface of the carrier substrate, an insulating material encapsulating the plurality of bonding wires, a component mounted on the insulating material, and a molding compound covering the top surface of the carrier substrate and encapsulating the semiconductor die, the plurality of bonding wires, the component and the insulating material.

CROSS REFERENCE TO RELATED APPLICATION

This is a continuation-in-part of U.S. application Ser. No. 15/176,163filed Jun. 8, 2016, which claims the priority from U.S. provisionalapplication No. 62/249,671 filed Nov. 2, 2015 and the priority from U.S.provisional application No. 62/251,775 filed Nov. 6, 2015. Thisapplication also claims the priority from U.S. provisional applicationNo. 62/527,186 filed Jun. 30, 2017. The above-mentioned applications areincluded in their entirety herein by reference.

BACKGROUND

The present disclosure relates generally to the field of semiconductorpackaging. More particularly, the present disclosure relates to asemiconductor integrated circuit (IC) package with multi-tier bondingwires and component(s) stacked directly on the multi-tier bonding wires.

In the integrated circuit (IC) packaging industry, there is a continuousdesire to provide higher and higher density IC packages forsemiconductor die having increasing numbers of input/output (I/O)terminal pads. When using a conventional wire bonding packagingtechnique, the pitch, or spacing between adjacent bonding wires becomesfiner and finer as the number of I/O terminal pads increases for a givensize die.

During the molding or encapsulation of a plastic IC package, the flow ofa plastic molding compound melt into a mold cavity exerts forcessufficiently high as to displace or deform the bonding wires, henceresulting in bonding wire sweep or mold wire sweep. The wire deformationcauses adjacent bond wires to come into contact with each other, whichresults in shorting between adjacent wires.

Although a variety of approaches have been suggested for reducing thebonding wire sweep during the encapsulating process of an IC package,many of these approaches require additional process steps or requirespecialized equipment. These requirements for additional process stepsor specialized equipment add to the costs of producing the package andare therefore undesirable.

SUMMARY

It is an object of the invention to provide an improved semiconductordevice and package having stabilized, insulator-coated bonding wires inorder to solve the above-mentioned prior art problems and shortcomings.

According to one aspect of the invention, a semiconductor packageincludes a carrier substrate having a top surface, a semiconductor diemounted on the top surface, a plurality of bonding wires connecting anactive surface of the semiconductor die to the top surface of thecarrier substrate, an insulating material encapsulating the plurality ofbonding wires, a component mounted on the insulating material, and amolding compound covering the top surface of the carrier substrate andencapsulating the semiconductor die, the plurality of bonding wires, thecomponent and the insulating material. The component may comprise adummy silicon die, a piece of metal, or a heat sink.

According to one embodiment, a semiconductor package includes a carriersubstrate having a top surface, a semiconductor die mounted on the topsurface, a plurality of first bonding wires connecting the semiconductordie to the carrier substrate, an insulating material encapsulating theplurality of first bonding wires, a component mounted on the insulatingmaterial, a plurality of second bonding wires connecting the componentto the carrier substrate, and a molding compound covering the topsurface of the carrier substrate and encapsulating the semiconductordie, the component, the plurality of first bonding wires, the pluralityof second bonding wires, and the insulating material. The component maycomprise a semiconductor die or a passive device.

According to another embodiment, a semiconductor package includes acarrier substrate having a top surface, a first semiconductor diemounted on the top surface, a plurality of first bonding wiresconnecting the first semiconductor die to the carrier substrate, a firstinsulating material encapsulating the plurality of first bonding wires,a second semiconductor die mounted on the first insulating material, aplurality of second bonding wires connecting the second semiconductordie to the carrier substrate, a second insulating material encapsulatingthe plurality of second bonding wires, a component mounted on the secondinsulating material, and a molding compound covering the top surface ofthe carrier substrate and encapsulating the component, the firstsemiconductor die, the second semiconductor die, the plurality of firstbonding wires, the plurality of second bonding wires, the firstinsulating material, and the second insulating material. The componentcomprises a passive device. A plurality of third bonding wires may beprovided for connecting the component to the carrier substrate.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention. In the drawings:

FIG. 1 is a schematic, cross-sectional diagram showing an exemplarysemiconductor package with coated bonding wires according to oneembodiment of the invention;

FIG. 2 is a schematic, perspective view of two adjacent bonding wires inFIG. 1 without the molding compound for clarity;

FIG. 3 is a schematic, cross-sectional diagram showing the two adjacentbonding wires and the coated insulating material;

FIG. 4 to FIG. 7 are schematic, cross-sectional diagrams showing anexemplary method for forming the semiconductor package with coatedbonding wires according to one embodiment of the invention;

FIG. 8 is a schematic top view of the semiconductor package showing anexemplary region around the semiconductor die, in which the insulatingmaterial is sprayed;

FIG. 9 is a schematic, cross-sectional diagram showing a dipping processfor coating an insulating material onto the bonding wires according toanother embodiment of the invention;

FIG. 10 is a schematic top view of a semiconductor IC package accordingto another embodiment of the invention;

FIG. 10A is a schematic top view of a semiconductor package according toyet another embodiment of the invention;

FIG. 11 is a schematic, cross-sectional view taken along line I-I′ inFIG. 10;

FIG. 12 shows the semiconductor IC package after molding;

FIG. 13 is a schematic top view of a semiconductor package according toanother embodiment of the invention;

FIG. 14 is a schematic, cross-sectional view taken along line II-II′ inFIG. 13.

FIG. 15 is a schematic, cross-sectional view of a semiconductor packageaccording to still another embodiment of the invention;

FIG. 16 is a schematic, cross-sectional view of a semiconductor packageaccording to still another embodiment of the invention; and

FIG. 17 is a schematic, cross-sectional view of a semiconductor packageaccording to still another embodiment of the invention.

DETAILED DESCRIPTION

In the following detailed description of embodiments of the invention,reference is made to the accompanying drawings, which form a parthereof, and in which is shown by way of illustration specific preferredembodiments in which the disclosure may be practiced.

These embodiments are described in sufficient detail to enable thoseskilled in the art to practice them, and it is to be understood thatother embodiments may be utilized and that mechanical, chemical,electrical, and procedural changes may be made without departing fromthe spirit and scope of the present disclosure. The following detaileddescription is, therefore, not to be taken in a limiting sense, and thescope of embodiments of the present invention is defined only by theappended claims.

Please refer to FIG. 1 and FIG. 2. FIG. 1 is a schematic,cross-sectional diagram showing an exemplary semiconductor package withcoated bonding wires according to one embodiment of the invention. FIG.2 is a schematic, perspective view of two adjacent bonding wires in FIG.1 without the molding compound for clarity.

As shown in FIG. 1 and FIG. 2, the semiconductor package 1 comprises acarrier substrate 10 having a top surface 10 a. A semiconductor die 20is mounted on the top surface 10 a. The semiconductor die 20 has anactive surface 20 a, on which a plurality of input/output (I/O) pads 210is distributed. According to the illustrative embodiment, thesemiconductor die 20 is electrically connected to the bond fingers 110on the top surface 10 a of the carrier substrate 10 through a pluralityof bonding wires 30. According to the illustrative embodiment, thebonding wires 30 may comprise copper, gold, silver, or any suitableconductive materials. According to the illustrative embodiment, thecarrier substrate 10 may comprise a packaging substrate, an interposersubstrate, or a leadframe substrate, but is not limited thereto.

According to the illustrative embodiment, the bonding wires 30 arepartially coated with an insulating material 40. According to theillustrative embodiment, the insulating material 40 may comprisepolymers, epoxy, or resins, but is not limited thereto. The insulatingmaterial 40 coated on the bonding wires 30 may be cured to provide thebonding wires 30 with extra mechanical support. The insulating material40 secures the bonding wires 30 and is able to resist the mold wiresweep during the encapsulation process of the semiconductor package 1.According to the illustrative embodiment, the insulating material 40 haslow permittivity or low dielectric constant (low-k) that can preventshorting and alleviate crosstalk between adjacent wires. In otherembodiments, the bonding wires 30 may be fully coated with theinsulating material 40 to provide a more desirable isolation effect.

According to the illustrative embodiment, the semiconductor package 1further comprises a molding compound 50 on the top surface 10 a of thecarrier substrate 10. The molding compound 50 encapsulates the bondingwires 30, the insulating material 40, and the semiconductor die 20.According to the illustrative embodiment, the molding compound 50 maycomprise an epoxy resin and a filler material, but is not limitedthereto. According to the illustrative embodiment, the insulatingmaterial 40 may have the same epoxy composition as that of the moldingcompound 50, but without the filler material or with lower content ofthe filler material. According to the illustrative embodiment, theinsulating material 40 contains less than 50 ppm halogen content inorder to prevent corrosion of the bonding wires 30. According to anotherembodiment, the insulating material 40 may have a composition that isdifferent from that of the molding compound 50.

As shown in FIG. 2, only two adjacent bonding wires 30 a and 30 b areillustrated for the sake of simplicity. The insulating material 40 ispartially coated on the portions of the two adjacent bonding wires 30 aand 30 b that are most likely to short to the adjacent wires during thewire sweep that occurs during the encapsulation process of thesemiconductor package 1. According to the illustrative embodiment, theinsulating material 40 may be also formed on the top surface 10 a of thecarrier substrate 10 or elsewhere in the semiconductor package 1. Theinsulating material 40 formed on the top surface 10 a of the carriersubstrate 10 may enhance the interface adhesive strength between themolding compound 50 and the carrier substrate 10.

The two adjacent bonding wires 30 a and 30 b may have different loopheights. It is advantageous to use the present invention because theinsulating material 40 coated on the bonding wires 30 a and 30 b canavoid abnormal wire sweep during encapsulation process and providesignificant isolation effect. Furthermore, the loop heights of the twoadjacent bonding wires 30 a and 30 b may be reduced such that more wirescan be arranged in the same space.

FIG. 3 is a schematic, cross-sectional diagram showing the two adjacentbonding wires and the coated insulating material. As shown in FIG. 3,according to the illustrative embodiment, the insulating material 40 mayonly cover at least a partial portion, for example upper half portion,of each of the bonding wires 30 when viewed in cross-sections of thebonding wires 30. According to the illustrative embodiment, the lowerhalf portion of each of the bonding wires 30 is not covered by theinsulating material 40. However, it is understood that, in someembodiments, each of the bonding wires 30 may be wrapped around by theinsulating material 40.

FIG. 4 to FIG. 7 are schematic, cross-sectional diagrams showing anexemplary method for forming the semiconductor package with coatedbonding wires according to one embodiment of the invention, wherein likenumeral numbers designate like layers, regions, or elements. As shown inFIG. 4, a semiconductor die 20 is mounted on a top surface 10 a of acarrier substrate 10. According to the illustrative embodiment, thecarrier substrate 10 may comprise a packaging substrate, an interposersubstrate, or a leadframe substrate, but is not limited thereto. Thesemiconductor die 20 may be adhered to the top surface 10 a by using anadhesive (not explicitly shown), but is not limited thereto. Accordingto the illustrative embodiment, the semiconductor die 20 is electricallyconnected to the bond fingers 110 on the top surface 10 a of the carriersubstrate 10 through a plurality of bonding wires 30.

After the wire-bonding process, an insulating material 40 is sprayedonto the bonding wires 30 within predetermined regions. For example,referring to FIG. 8, a region 140 is demonstrated around thesemiconductor die 20. The insulating material 40 may be sprayed onto thebonding wires 30 within the region 140 that would be most likely toshort to the adjacent wires during the encapsulation process. Accordingto the illustrative embodiment, the insulating material 40 may besprayed onto the top surface 10 a of the carrier substrate 10 or ontothe active surface 20 a of the semiconductor die 20, which may enhancethe interface adhesive strength between the molding compound and thesubstrate surface/die surface. It is understood the region 140 shown inFIG. 8 is for illustration purposes only.

According to the illustrative embodiment, the insulating material 40 maybe sprayed onto the bonding wires 30 by using a jet sprayer 400 or thelike. However, in some embodiments, the insulating material 40 may becoated onto the bonding wires 30 by using a dipping process. Forexample, referring to FIG. 9, a container 500 contains the insulatingmaterial 40 in liquid phase. The package 1 is flipped and the bondingwires 30 may be partially dipped into the insulating material 40 to coatthe bonding wires 30. Subsequently, a drying process or baking processmay be performed to remove the solvent.

As shown in FIG. 6, after spraying the insulating material 40, anoptional curing process 600 may be carried out to cure the insulatingmaterial 40. According to the illustrative embodiment, the curingprocess 600 may be carried out in an oven or under actinic radiationconditions, but is not limited thereto. For example, the curing process600 may be a fast curing process under ultraviolet (UV) or infrared (IR)irradiation. It is understood that the curing process 600 may be skippedin some embodiments, and the insulating material 40 may be cured at alater stage, together with the molding compound.

As shown in FIG. 7, a molding compound 50 is formed on the top surface10 a of the carrier substrate 10 to encapsulate the bonding wires 30,the insulating material 40, and the semiconductor die 20. According tothe illustrative embodiment, the molding compound 50 may comprise anepoxy resin and a filler material, but is not limited thereto. Accordingto the illustrative embodiment, the insulating material 40 may have thesame epoxy composition as that of the molding compound 50, but withoutthe filler material or with lower content of the filler material.According to the illustrative embodiment, the insulating material 40contains less than 50 ppm halogen content in order to prevent corrosionof the bonding wires 30.

Please refer to FIG. 10 to FIG. 12. FIG. 10 is a schematic top view of asemiconductor package according to another embodiment of the invention.FIG. 11 is a schematic, cross-sectional view taken along line I-I′ inFIG. 10. FIG. 12 shows the semiconductor package after molding. Likelayers, regions or elements are designated by like numeral numbers.

As shown in FIG. 10 and FIG. 11, the semiconductor package 2 comprises acarrier substrate 10 having a top surface 10 a and a bottom surface 10b. A semiconductor die 20 is mounted on the top surface 10 a. Thesemiconductor die 20 has an active surface 20 a, on which a plurality ofinput/output (I/O) pads 210 is distributed. According to theillustrative embodiment, the semiconductor die 20 is electricallyconnected to the bond fingers 110 on the top surface 10 a of the carriersubstrate 10 through multi-tier bonding wires 30. According to theillustrative embodiment, the bonding wires 30 may comprise copper, gold,silver, or any suitable conductive materials. According to theillustrative embodiment, the carrier substrate 10 may comprise apackaging substrate or an interposer substrate, but is not limitedthereto.

According to the illustrative embodiment, an insulating material 41 isapplied to the bonding wires 30. For example, the insulating material 41may be applied in a rectangular, ring shape around or about thesemiconductor die 20, but is not limited thereto. The insulatingmaterial 41 may completely cover the multi-tier bonding wires 30 and isin direct contact with only a peripheral region of the active surface 20a. However, it is understood that the insulating material 41 may coversonly a portion of the bonding wires 30. The ring-shaped insulatingmaterial 41 may be continuous or may be discontinuous. According to theillustrative embodiment, the insulating material 41 may be in directcontact with the sidewalls of the semiconductor die 20.

According to the illustrative embodiment, the insulating material 41 maycomprise polymers, epoxy, fillers, or resins, but is not limitedthereto. The insulating material 41 coated on the bonding wires 30 maybe cured to provide the bonding wires 30 with extra mechanical support.The insulating material 41 secures the bonding wires 30 and is able toresist the mold wire sweep during the subsequent encapsulation process.According to the illustrative embodiment, the insulating material 41 haslow permittivity or low dielectric constant (low-k) that can preventshorting and alleviate crosstalk between adjacent wires.

According to the illustrative embodiment, a component 200 is mounteddirectly on the insulating material 41. For example, the component 200may be a dummy silicon die, a piece of metal, or a heat sink, but is notlimited thereto. The component 200 may be attached to the insulatingmaterial 41 by using an adhesive or a glue layer 202. According to theillustrative embodiment, the component 200 may have a slender shape andits longer axis may extend along the diagonal direction of thesemiconductor package 2, as can be seen in FIG. 10. The mold flowdirection may be orthogonal to the longer axis of the component 200.According to another embodiment, as shown in FIG. 10A, the longer sideof the component 200 may be in parallel with the longer side of thesemiconductor package 2.

As shown in FIG. 12, a molding compound 50 is formed on the top surface10 a of the carrier substrate 10 to encapsulate the bonding wires 30,the insulating material 41, the component 200, and the semiconductor die20. According to the illustrative embodiment, the molding compound 50may comprise an epoxy resin and a filler material, but is not limitedthereto. According to the illustrative embodiment, the insulatingmaterial 41 may have the same epoxy composition as that of the moldingcompound 50, but without the filler material or with lower content ofthe filler material. According to the illustrative embodiment, theinsulating material 41 and the molding compound 50 have differentcompositions. According to the illustrative embodiment, the insulatingmaterial 41 contains less than 50 ppm halogen content in order toprevent corrosion of the bonding wires 30. After the molding compound 50is formed, connection elements 60 such as solder balls are formed on thebottom surface 10 b.

FIG. 13 is a schematic top view of a semiconductor package according toanother embodiment of the invention. FIG. 14 is a schematic,cross-sectional view taken along line II-II′ in FIG. 13. Like layers,regions, or elements are designated by like numeral numbers. As shown inFIG. 13 and FIG. 14, likewise, the semiconductor package 3 comprises acomponent 200 directed mounted on the insulating material 41. Accordingto the illustrative embodiment, the component 200 may be a semiconductordie and is wired bonded to the carrier substrate 10 through the bondingwires 31. The component 200 completely overlaps with the underlyingsemiconductor die 20. As cane be seen in FIG. 13, the surface area ofthe component 200 is greater than that of the underlying semiconductordie 20. The component 200 has a length L. The component 200 is supportedby the insulating material 41 and the bonding wires 30, 31. An overhang230 having a distance t between an edge of the component 200 and thecontact point CP between the component 200 and the insulating material41 is shown in FIG. 14. The overhang distance t may be greater than ⅓Land may be smaller than ½L.

The molding compound 50 is formed on the top surface 10 a of the carriersubstrate 10 to encapsulate the bonding wires 30, 31, the insulatingmaterial 41, the component 200, and the semiconductor die 20. Themolding compound 50 may be formed by transfer mold or compression mold,but is not limited thereto.

FIG. 15 is a schematic, cross-sectional view of a semiconductor packageaccording to still another embodiment of the invention, wherein likelayers, regions, or elements are designated by like numeral numbers. Asshown in FIG. 15, likewise, the semiconductor package 4 comprises acomponent 200 directed mounted on the insulating material 41. Accordingto the illustrative embodiment, the component 200 may be a semiconductordie and is wired bonded to the carrier substrate 10 through the bondingwires 31. According to the illustrative embodiment, an insulatingmaterial 42 may be applied to the bonding wires 31 so as to secure thebonding wires 31 and provide the bonding wires 31 with extra mechanicalsupport. According to the illustrative embodiment, components 300 may bemounted directly on the insulating material 42 via adhesive layers 302.For example, the components 300 may comprise discrete passive devicesincluding, but not limited to, capacitors, resistors or inductors.According to the illustrative embodiment, components 300 may be wirebonded to the carrier substrate 10 and/or the component 200 through thebonding wires 32. The molding compound 50 is formed on the top surface10 a of the carrier substrate 10 to encapsulate the bonding wires 30,31, 32, the insulating material 41, 42, the component 200, thecomponents 300, and the semiconductor die 20.

FIG. 16 is a schematic, cross-sectional view of a semiconductor packageaccording to still another embodiment of the invention, wherein likelayers, regions, or elements are designated by like numeral numbers. Asshown in FIG. 16, the difference between the semiconductor package 5 inFIG. 16 and the semiconductor package 3 in FIG. 14 is that thesemiconductor package 5 in FIG. 16 comprises a spacer 700 between thecomponent 200 and the semiconductor die 20. The spacer 700 may beadhered to the active surface 20 a of the semiconductor die 20 by usingan adhesive layer 702.

FIG. 17 is a schematic, cross-sectional view of a semiconductor packageaccording to still another embodiment of the invention, wherein likelayers, regions, or elements are designated by like numeral numbers. Asshown in FIG. 17, the semiconductor package 6 comprises components 200directed mounted on the insulating material 41. According to theillustrative embodiment, the components 200 may comprise a semiconductordie or a passive device such as a capacitor, a resistor or an inductor.The components 200 may be wired bonded to the carrier substrate 10and/or the semiconductor die 20 through the bonding wires 31. Themolding compound 50 is formed on the top surface 10 a of the carriersubstrate 10 to encapsulate the bonding wires 30, 31, the insulatingmaterial 41, the components 200, and the semiconductor die 20.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

1-22. (canceled)
 23. A semiconductor package, comprising: a carriersubstrate having a top surface; a semiconductor die mounted over the topsurface; a first plurality of bonding wires connected to the topsurface; a second plurality of bonding wires connected to the topsurface; a first insulating material encapsulating the first pluralityof bonding wires; a second insulating material encapsulating the secondplurality of bonding wires; a first component mounted on the firstinsulating material; and a second component mounted on the secondinsulating material.
 24. The semiconductor package of claim 23, furthercomprising: a third plurality of bonding wires connected to the topsurface and the semiconductor die; a fourth plurality of bonding wiresconnected to the top surface and the semiconductor die; a thirdinsulating material encapsulating the third plurality of bonding wires;a fourth insulating material encapsulating the fourth plurality ofbonding wires; and a third component mounted on the third insulatingmaterial and the fourth insulating material.
 25. The semiconductorpackage of claim 23, wherein the first and second plurality of bondingwires are further connected to the third component.
 26. Thesemiconductor package of claim 25, further comprising a fifth pluralityof bonding wires connected to the top surface and the first component.27. The semiconductor package of claim 26, further comprising a sixthplurality of bonding wires connected to the top surface and the secondcomponent.
 28. The semiconductor package of claim 23, wherein the firstplurality of bonding wires and the second plurality of bonding wires areconnected to the semiconductor die.
 29. The semiconductor package ofclaim 28, further comprising at least one bonding wire connecting thefirst component to the semiconductor die.
 30. The semiconductor packageof claim 29, further comprising at least one bonding wire connecting thesecond component to the semiconductor die.
 31. The semiconductor packageof claim 23, wherein the first plurality of bonding wires physicallysupport the first component.
 32. The semiconductor package of claim 31,wherein the second plurality of bonding wires physically support thesecond component.
 33. The semiconductor package of claim 23, furthercomprising a molding compound covering the top surface of the carriersubstrate and encapsulating the semiconductor die, the first and secondplurality of bonding wires, the first and second components and thefirst and second insulating materials.
 34. The semiconductor packageaccording to claim 23, wherein the first component is attached to thefirst insulating material by an adhesive layer.
 35. The semiconductorpackage according to claim 23, wherein the first and second insulatingmaterial is disposed in a rectangular, ring shape around thesemiconductor die.
 36. The semiconductor package according to claim 23,wherein the carrier substrate comprises a packaging substrate or aninterposer substrate.
 37. The semiconductor package according to claim23, wherein the first component comprises a semiconductor die or apassive device.